(1) Field of the Invention
The present invention relates to underwater vehicles which can be unmanned and untethered and more particularly to an underwater vehicle having facility for affixing to and maintaining station on an underwater hull portion of another marine vehicle.
(2) Description of the Prior Art
Underwater vehicles are known and are used for a variety of missions, including anti-mine operations, oceanographic analysis, reconnaissance, intelligence gathering, and tracking of marine vehicles. These vehicles can be either manned or more commonly unmanned. Retrieval of underwater vehicles which have completed their missions has heretofore involved a submarine or other naval vessel maneuvering alongside the underwater vehicle and mechanically grabbing the underwater vehicle. Maneuvering a submarine is much more difficult than maneuvering an underwater vehicle. In addition, the underwater vehicle is sometimes in high sea states or near dangerous coastal obstacles. Maintaining stealth is more difficult with a large submarine than with an underwater vehicle. Accordingly, there is a need for an underwater vehicle which can maneuver to engage a retrieving vehicle, whether submarine or surface vessel, and cling to the hull of the retrieving vehicle until the retrieving vehicle reaches a safe location for removal of the underwater vehicle.